What is CVE-2026-42790?

CVE-2026-42790 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. nameConstraints DNS bypass via subject CommonName fallback in public_key hostname verification

Which CVE IDs does CVE-2026-42790 cover?

CVE-2026-42790 covers the following CVE IDs: CVE-2026-42790. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

Which products are affected by CVE-2026-42790?

CVE-2026-42790 affects 1 product, including: azl3 erlang 26.2.5.20-1 on Azure Linux 3.0.

CVE-2026-42790High

nameConstraints DNS bypass via subject CommonName fallback in public_key hostname verification

Vendor

Microsoft Security Response Center (MSRC)

Published

June 1, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-42790 →

🎯 Affected products1

azl3 erlang 26.2.5.20-1 on Azure Linux 3.0

✅ Remediation

KBCBL-Mariner Releases (Security Update) — fixed build 26.2.5.21-1

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42790
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade